hypoxia as well as to socioeconomic, nutritional and environmental factors. Objectives: To compare physical growth of school children in Peruvian urban areas at sea level (150 meters above sea level) and moderate altitude (2 320 m.a.s.l.). Design: Ex post facto design, descriptive comparative study. Institution: Faculty of Physical Education, State University of Campinas, SP, Brazil, and Universidad Nacional de Educacion, Lima, Peru. Participants: School children. Interventions: A total of 1 153 boys and girls aged 6 to 11 years were selected from two Peruvian geographical regions, one at sea level (SL) (Lima-East; 150 m.a.s.l.) and the other at moderate altitude (MA) (urban Southern Arequipa; 2 320 m.a.s.l.). School children at SL were chosen in non-probabilistic intentional way, totaling a subsample of 672 children. Pupils at moderate altitude (MA) were selected by stratified probabili...